1. www.fs-world.com [ 56 ] Spring 2011 edition
Anthony Gee is the Stat-X Product and Special Applications Manager at Fireaway.
Mr. Gee is a Mechanical Engineer and has worked in the Special Hazards fire protection
industry for over 20 years. Throughout his career Mr. Gee has worked for various well
known fire detection and fire suppression manufacturers and supplied integrated fire
protection systems for industrial, offshore, marine, and naval projects
in the global market.
By Anthony Gee
CONDENSED AEROSOL
The International Montreal Protocol on Substances That
Deplete the Ozone Layer, which entered into force on
January 1, 1989, set the timescale for the cessation of
production of specific ozone depleting chemical compounds
for the end of 1993 in the developed world and 2010 in
developing countries. The NFPA 12A Halon 1301 (also
known as bromotrifluoromethane CF3Br), an effective and
widely used chlorofluorocarbon (CFC) fire extinguishing
gas agent has the highest ozone depletion potential of
any man-made ozone depleting substances, consequently
ending production of this agent in the United States in
1994 in compliance with the US Clean Air Act of 1990.
Manufacturers of fire suppression technologies quickly
recognized the impact the phase-out of the production of
Halon 1301 would have on the fire protection market,
resulting in the entry of Halon 1301 replacement gaseous
and water-based products in the early 1990’s such as the
NFPA 2001 halocarbon (HFC) agents and NFPA 750 water-
mist technologies. However, despite the rapid development
of these technologies to provide similar fire protection as
Halon 1301, none of the technologies could replace Halon
1301 on a one-to-one basis by stored agent weight and
volume. Clearly the need for true Halon 1301 replacement
technology was not completely satisfied.
The U.S. EPA first formally recognized condensed aerosol
technology (also referred to as inert gas/powdered aerosols)
as an acceptable Halon 1301 substitute as early as 1995
(Federal Register Vol. 60, Number 113, June 13, 1995).
The early condensed aerosol fire suppression technologies
became commercially available in the international fire
protection market during the mid-1990’s. It was essentially
derived from the development of the technology by former
Soviet Union for their military and their space programs
around the 1970's.
Condensed aerosol systems have been commercially sold
and installed in the international market for over a decade.
In the late 1990’s the European and Australian marine
classification societies and approval agencies began to
issue approval certificates for aerosol units for the protection
of the engine rooms of small recreational and commercial
vessels. However, with the exception of research by a few
US government defense laboratories, the technology
remained little known in the United States industrial fire
protection market. That is, until recently.
FIRE DETECTION
AND EXTINGUISHING SYSTEMS

2. www.fs-world.com [ 57 ] Spring 2011 edition
In 2006, NFPA recognized aerosol fire
suppression agents as a distinct tech-
nology from existing gaseous total
flooding agents such as the NFPA
2001 halocarbon, fluoroketone, inert
gas clean agents, and NFPA 12 carbon
dioxide gas. They voted to release
NFPA 2010, the Standard for Fixed
Aerosol Fire-Extinguishing Systems.
ULC Underwriters Laboratories of Can-
ada, Inc. was the first agency in North
America to formally list aerosol fire
suppression systems under a new
category FWSAC, tested in accor-
dance with UL 2127, the same test
standard used to list NFPA 2001 inert
gas fire suppression systems.
UL Underwriters Laboratories Inc. in
November 2008 became the first
agency in North America to release a
standard specifically for Fixed Con-
densed Aerosol Extinguishing System
Units, UL Subject 2775, and to list
products under their category FWSA.
Together with the NFPA 2010 standard
(recently revised to the 2010 edition)
UL have joined the US EPA in recog-
nizing aerosols fire suppression sys-
tems as a distinct, viable, and effective
Halon alternative technology.
CONDENSED AEROSOL
TECHNOLOGY
The flame quenching capability of the
potassium ion (or radical) is well known
and potassium-based compounds
used as flame-halting agents have
been proven in highly effective fire
suppression agents such as Purple-
K dry chemicals (potassium bicarbon-
ate KHCO3 based mixed with other
chemicals) and Karbaloy wet agents
(potassium carbonate K2CO3 based
mixed with water).
Fire extinguishing systems producing
ions that directly inhibit the chemical
chain reaction that forms one of the
four sides of the fire tetrahedron (Heat
– Oxygen – Fuel – Chemical Reaction)
is not new. For example, the Halon
1301 and Halon 1211 agents (produc-
ing bromine ions) have been widely
used for the fire protection of special
Figure 2. Stat-X Electric Operated Aerosol Generators
Figure 1. Stat-X 30T generator extinguishing a flammable liquid fire in one second

3. www.fs-world.com [ 58 ] Spring 2011 edition
hazards against Class A surface, B,
and C fires since the 1960’s.
The invention of condensed aerosol
fire extinguishing technology has dis-
covered a revolutionary method to
disperse, as a total flooding agent,
potassium based micro-particles pro-
pelled by inert gases. Condensed
aerosol, as defined in NFPA 2010, is
an extinguishing medium consisting
of finely divided solid particles, generally
less than 10 microns in diameter, and
gaseous matter, generated by a com-
bustion process of a solid aerosol-
forming compound.
Based on Stokes Law, the settling
velocities for fine solid spherical parti-
cles in air over a retention period of
10 minutes can be determined (ref.:
NFPA 2010, 2010 ed., Table C.4).
Particles with mass median aerody-
namic diameter (MMAD) < 10 microns,
the vast majority of particles, will remain
suspended during the retention period.
Particles with MMAD > 10 microns
(micrometer) will agglomerate and fall
out of suspension.
To illustrate, the Fireaway LLC Stat-
X® aerosol microparticles will have a
MMAD of 1-2 microns with a setting
velocity of 0.0035 to 0.013 cm/s. Gen-
erally Purple-K dry chemical particles
will have a MMAD greater than 20
microns with a settling velocity of 1.2
cm/s, 90-340 times that of the Stat-
X aerosol particles. Clearly once dis-
persed aerosol fire extinguishing
agents will tend to remain suspended
in air over a long period of time, com-
pared with the much larger dry chem-
ical particles which will quickly settle
within seconds forming significant sur-
face residue. Once fires are extin-
guished, the suspended aerosol
agents remain buoyant in air and can
be naturally or forced vented from the
protected area before the micro-
particles can settle. Consequently,
when properly vented during post-fire
operations, aerosol systems will leave
little residue.
FIRE SUPPRESSION
MECHANICS
During combustion, the flame propa-
gation radicals including hydroxyl OH,
hydrogen H and oxygen O sustain the
flame chemical chain reaction. Con-
densed aerosol microparticles gener-
ally consist of a large population of
solid potassium carbonate K2CO3 and
potassium bi-carbonate KHCO3 com-
pounds generated from a proprietary
aerosol forming solid pellet stored
inside a fire extinguishing unit. The
pellet also generates inert nitrogen gas
which entrains and propels the potas-
sium microparticle compounds into
the protected space in the form of an
aerosol cloud.
The cloud, composed of a large popu-
lation of dispersed microparticles, col-
lectively offers a very large surface area
for the absorption of heat. Thermal
cooling of the flame temperature will
occur as the potassium solid com-
pounds absorb heat and vaporize to
gas. Dilution of the fire combustion
zone with aerosol microparticles and
inert gases will slow down the velocity
of the flame front propagation and inhibit
additional fuel molecules from partici-
pating in the combustion process.
On the surface of the particles recom-
bination of the flame propagation rad-
Figure 3. Stat-X 100E and 250E Generators Discharging
Figure 4. Stat-X Thermal/Manual Operated Aerosol Generators

4. Enquiry Card No. 306

5. www.fs-world.com [ 60 ] Spring 2011 edition
icals OH, H, and O will take place to
form OH and water molecules.
Endothermic chemical reactions take
place where potassium radicals K are
generated and will combine with the
flame radicals OH and O to form po-
tassium hydroxide KOH and potassi-
um oxygen KO. The KOH compound
will further combine with the H radical
to release more potassium radicals K.
The population of potassium radicals
is therefore propagated since they are
both consumed and produced by the
reaction with the fire free radicals.
Generally the common byproduct from
these chemical reactions is the water
molecule H2O.
Condensed aerosol fire extinguishing
systems consequently attack all four
sides of the fire tetrahedron. The en-
hanced fire suppression efficiency of
condensed aerosol systems is such
that when designed as total flooding
systems to extinguish Class B flam-
mable liquid fires, the mass flooding
rate per volume for condensed aerosol
systems is five times less than an
equivalent NFPA 12A Halon 1301 sys-
tem, 10 times less than an equivalent
NFPA 2001 halocarbon clean agent
system, and 14 times less than an
equivalent NFPA 12 carbon dioxide
system.
STAT-X AEROSOL FIRE
SUPPRESSION PRODUCTS
Fireaway, a Minneapolis based com-
pany founded in 2005 has developed
a family of products under the brand
name of Stat-X that is compliant with
NFPA 2010 and the first manufacturer
listed by UL under category FWSA. The
Stat-X products are UL listed for Class
A and B fires, and Class C (with Class
A and B involvement). Stat-X fire detec-
tion and extinguishing systems are
approved on the EPA SNAP List for
normally unoccupied and unoccupied
spaces.
The product lines include three families
of fixed and portable fire suppression
units of similar design but with different
methods of application: electric release
with a fire detection system, automat-
ic/mechanical release as a stand-alone
fire extinguishing unit with integral fixed-
temperature heat detector, portable
hand tossed unit for local area flame
suppression and control. All units sup-
plied for fixed fire extinguishing applica-
tions are hermetically sealed generators
of stainless steel construction.
The patented Stat-X electric operated
aerosol generators are available in units
with integral aerosol forming com-
pounds supplying 30, 60, 100, 250,
500, 1000, 1500, and 2500 grams of
aerosol fire suppressant agent. The
electrically activated generators, when
coupled with a fire detection and re-
leasing panel and appropriate detec-
tion devices, provide a fire suppression
system that is significantly more cost
effective than any other available tech-
nology. The family of generator sizes
allows precise tailoring of systems to
specific hazards. The generators are
ruggedly constructed of exterior and
interior stainless steel shells and her-
metically sealed with a non-permeable
membrane to insure reliability and long
service life in even the most aggressive
environments. The units are non-
pressurized prior to system activation.
Upon activation, the generators pro-
duce an exceptionally efficient, ultra-
fine, potassium based aerosol fire sup-
pression agent which is environmen-
tally friendly - having no ozone deple-
tion or global warming potential.
Stat-X thermal and manual operated
units are optional alternatives to elec-
trically operated units, and are used
as stand-alone fire suppression for
smaller enclosed spaces. Units are
available in sizes 30, 60, 100, 250,
and 500 grams of aerosol agents. Unit
design is identical to electrically oper-
ated units except for actuation method.
The automatic unit is fitted with a
thermal actuator that will function as
a fixed temperature heat detector. The
thermal actuator will activate the gen-
erator at 158°F/70°C, 203°F/95°C, or
254°F/123°C. The thermal actuator is
available in either anodized aluminum
or 316 stainless steel. The ther-
mal/manual and manual-only operated
unit can be operated by cable pull
action.
A hand deployable unit called First
Figure 5. Stat-X First Responder®
Figure 6. Demonstration by fire fighters using two Stat-X First Responder
hand-held units

6. www.fs-world.com [ 61 ] Spring 2011 edition
Responder® produces the same highly
effective fire suppression agent as that
of the fixed systems and is designed
to be used by trained professionals
as a first response tool in emergency
fire events. The First Responder has
been successfully used by fire fighters,
military organizations, public utilities,
and large enterprise customers to
knockdown and suppress the growth
of random fires.
The First Responder has a similar de-
sign and the same agent capacity as
the 500E and 500T generators, but
has a much lighter construction. Fitted
with a five-second-time delay release
device, the First Responder is tossed
into fires in any enclosed space, effec-
tively knocking-down the flames, reduc-
ing the size of the fire, containing further
spread of the fire, and under certain
conditions extinguishing the fire.
The unit has been deployed by fire
departments to control the spread of
fires in basements, enabling fire fighters
to extinguish fires with reduced re-
sources and water damage.
The First Responder has been proven
to provide utilities an effective fire-fighting
tool to combat manhole fires. Fitted to
vehicles, trained maintenance personnel
can drop these units down manholes
to assist in the evacuation of technicians
underground in a fire event.
It is an environmentally friendly total
flooding system listed to provide Class
C fire protection for rooms with elec-
tronic and electrical equipment.
quate. Stat-X systems have been in-
stalled in machine tools and success-
fully extinguished numerous fires in
protected machines.
Automatic fire suppression system for
the protection of rolling stock, passen-
ger, and heavy vehicles has been de-
veloped. Aerosol technology offers to
vehicle manufacturers and operator’s
one of the most compact, environmen-
tally friendly, maintenance free engine
compartment protection systems avail-
able on the market today.
The aerosol generators are so tough
they are currently installed in the engine
compartments of thousands of military
armored mine-resistant all terrain ve-
hicles. The commercial off-the-shelf
generators have shown themselves
to meet extreme test conditions of US
military standards and are also being
installed for the protection of automo-
bile engines.
In the USA, NFPA reports that fire
departments respond to over 2,000
passenger and school bus fires annu-
ally. The aerosol compact lightweight
products can be fitted in the bus en-
gine compartment and has been suc-
cessfully tested in accordance with
the Swedish Fire Protection Associa-
tion Standard SBF 128:1 Guidelines
for fixed automatic fire suppression
Car Engine Compartment Protection
Typical Stat-X Server and Telecom Room Installation
CNC Machine Tool Installaton
CNC machines are well designed,
however, this equipment may be using
oil-based coolants (typically petroleum
or mineral oil) such as in drilling,
broaching, tapping, grinding, and hon-
ing operations. These types of oils are
also combustible and susceptible to
flash fires. A fire event in these ma-
chines can be catastrophic to the
operator and can result in significant
property damage and production
down time if fire protection is inade-

7. www.fs-world.com [ 62 ] Spring 2011 edition
systems for buses and coaches. The
suppression system is designed to
interface with a fire detection system
or with the bus management system.
The aerosol systems are also offered
with thermal or mechanical manual
release actuators for those applications
where electric power sources are un-
available.
The aerosol systems has been installed
in commercial vessels, carrying many
international marine certifications and
acceptance for the protection of
yachts, fishing vessels, tugboats, and
small commercial vessels including
ABS, BV, RINA, DNV, ECB, and Flag
authorities including the UK MCA,
Australia, New Zealand, Norway, Swe-
den, and Iceland.
US Navy researchers recently com-
pleted highly successful tests to dem-
onstrate the effectiveness of propelled
extinguishing agent technology (PEAT)
to protect the air cushion landing craft
turbine engine enclosures, auxiliary
power units, and fuel bay compart-
ments. The class of PEAT generators
chosen was solid particle (condensed)
aerosol-type generators because of
their technology maturity, commercial
availability, and its environmental ac-
ceptability related ODP and GWP. Dur-
ing navy fire testing, the PEAT aerosol
units were able to extinguish all of the
Class B pool and Class B spray fire
threats and meet the Naval Sea Sys-
tems Command established require-
ments for re-ignition mitigation. The
successes of this fire test series offer
a more than a 50% reduction in weight
and maintenance-free fire protection
option for future navy vessels. The
aerosol generators were tested as part
of the Navy test program.
When NASA Kennedy Space Center’s
fire safety experts decided to replace
the fire suppression system in its giant
twin crawler transporters, it turned to
the aerosol system as the next gener-
ation firefighting system for the crawler
enclosed spaces. The crawlers, which
were built in 1966 and are two of the
world’s largest moving machines, still
carry space shuttles to the Kennedy
launch pads for liftoff. They are com-
plex environments with a great deal
of equipment packed into tight spaces,
which makes the piping for gaseous
fire suppression systems very cumber-
some and expensive. NASA has in-
stalled approximately 100 Stat-X gen-
erators for the control areas, machine
rooms, and communication rooms in
both its crawlers.
NFPA 2010 aerosol systems are suit-
able for special hazards applications
as replacements for Halon 1301 sys-
tems and high-pressure carbon dioxide
systems. NFPA 2010 systems can
also be used as alternatives for SNAP
List technologies such NFPA 2001
clean agent systems and NFPA 750
water mist systems.
These systems can be used to protect
applications such as:
•Telecommunications Facilities
• Flammable Liquid Storage Areas
• Data Processing Facilities
• Marine Engine Rooms*
• Process Control Rooms
• High Value Mobile Equipment*
• Power Plants
• Storage Vaults
• Turbine Enclosures
• CNC and other High Value
Machines
NASA Crawler Transporter
Bus Engine Compartment Protection